I made a birthday cake this weekend and it was a hit, too good to not share!
I used a traditional double chocolate cake mix - the trick is in the add ins! All you have to do to make it super moist is swap out the water for chocolate milk in equal parts. This really makes a difference as you will have to refrigerate this cake due to the frosting, and the fridge generally dries out boxed cakes.
For the Frosting:
This is super simple.
Start by mixing 1 cup of softened butter with 1 cup of peanut butter* until it is blended.
Next, add in 1/4 cup of milk and 1 teaspoon of vanilla extract until blended.
Finish it off by slowly incorporating 4 cups of powdered sugar, and then beat on high for 30 seconds.
*Note: Peanut butter icing generally calls for more peanut butter than 1 cup, but to give it the true "Reese's Pieces" taste, I cut back on the peanut butter
Crumb coat the cake and press Reese's Pieces candies on the sides. Frost top of cake using a spoon, gently pulling spoon up in circles to create a textured top.